Festival season kicks off properly this weekend with Glastonbury, heralding another depressingly typical year of male-dominated line-ups. As a female musician currently in two mixed-gender bands, I have always been painfully aware of my minority status in the music scene.

As an annual yardstick of Britain's musical talent, summer festivals help to shape the male-dominated status quo. So, as an experiment to visually represent the issue of gender inequality in music, I edited the posters of some of Britain's best-loved festivals – Glastonbury, Bestival, and Reading and Leeds – deleting all the acts with no female members.

The results are as striking as they are shocking: blank spaces flood what would otherwise be a crowded list of artists.

After a quick count, Glastonbury is not the worst offender, and female co-organiser Emily Eavis must play a part in this.

Glastonbury 2013's poster with male-only acts removed

Still, only 34% of its poster advertised acts containing any female artists (not including backing singers or session musicians). And unlike 2011 when Beyoncé headlined, by my calculation just eight female musicians on the lineup will tread their dainty feet on the Pyramid Stage this year.

Only 21% of Bestival acts feature women; and at Reading and Leeds, a pitiful 17% acts contain women.

Bestival 2013's acts with at least one female member

Still, festivals alone are not to blame: promoters, managers and record labels all play their part. As a society we are less encouraging of girls who aspire to headline Glastonbury. I was lucky. My mother is a musician who started out in the 70s and always told me my XX chromosome was no barrier to making music.